A substrate treating apparatus includes a support table for receiving a carrier (container) constructed to contain a plurality of substrates (wafers) as arranged at intervals in a vertical direction, a treating section for performing predetermined treatments of the substrates, and a substrate transport mechanism provided between the support table and the treating section. The substrate transport mechanism has a hand for holding the substrates to take the substrates out of the carrier, transport the substrates to the treating section, transport the substrates from the treating section to the carrier, and deposit the substrates in the carrier.
The support table includes one transmission type sensor (mapping sensor) set having a light transmitter and a light receiver. The light transmitter and light receiver are opposed to each other across part of edge regions of the circular substrates, from positions forward of the substrates along substrate surfaces (see Japanese Unexamined Patent Publication No. 2009-049096, for example). This transmission type sensor is vertically movable in the vertical direction of arrangement of the substrates within the carrier to detect the number and positions of the substrates in the carrier, and also to detect whether or not the substrates are arranged on top of one another.
Further, a plurality of transmission type sensor sets are provided in a fore-and-aft direction (depth direction) in which substrates are transported into and out of a carrier, to be able to detect the number and positions of the substrates in the carrier, and also to detect protrusions of the substrates from the carrier (see Japanese Unexamined Patent Publication No. 2009-049096, for example).
Japanese patent No. 5185417 describes a carrier for eliminating a problem of vibration or bouncing of substrates occurring at times of transportation.
Japanese Unexamined Patent Publication H9-148404 describes preventing collision between a substrate transport arm and substrates by detecting vertical “clearances” between the substrates contained in a cassette, and varying operation of the substrate transport arm according to the clearances. Japanese Unexamined Patent Publication No. 2012-235058 describes a safe unloading of substrates from a cassette achieved by calculating “clearances” between the substrates contained in multiple vertical stages in the cassette, and determining from the clearances whether a robot hand can advance into the cassette or not.